Small Fix for js-unzip

Hi August,

I've been using js-unzip at magicscroll.net.  It works brilliantly.

I was sent an epub file by a user that js-unzip crashed on because it used the bit3trailingdatadescriptor.  I've made a one line modification to js-unzip.js to ignore this information and correctly skip to the next file. This allows the file to be unpacked without issue.

I don't work on Windows which made the current test difficult to run so I've also added a new test in test/integration called inline_test.html  that works in chrome.  It unzips 3 zip files that are base64 encoded in base64example.js.  The original js-unzip fails on the 3rd entry in base64example.js which is a modified version of the original failing file that I received.

Kind Regards
Richard Wallis